// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_DNS_HOST_RESOLVER_MOJO_H_
#define NET_DNS_HOST_RESOLVER_MOJO_H_

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/threading/thread_checker.h"
#include "net/dns/host_cache.h"
#include "net/dns/host_resolver.h"
#include "net/interfaces/host_resolver_service.mojom.h"

namespace net {
class AddressList;
class BoundNetLog;

// A HostResolver implementation that converts requests to mojo types and
// forwards them to a mojo Impl interface.
class HostResolverMojo : public HostResolver {
public:
    class Impl {
    public:
        virtual ~Impl() = default;
        virtual void ResolveDns(interfaces::HostResolverRequestInfoPtr,
            interfaces::HostResolverRequestClientPtr)
            = 0;
    };

    // |impl| must outlive |this|.
    explicit HostResolverMojo(Impl* impl);
    ~HostResolverMojo() override;

    // HostResolver overrides.
    // Note: |Resolve()| currently ignores |priority|.
    int Resolve(const RequestInfo& info,
        RequestPriority priority,
        AddressList* addresses,
        const CompletionCallback& callback,
        RequestHandle* request_handle,
        const BoundNetLog& source_net_log) override;
    int ResolveFromCache(const RequestInfo& info,
        AddressList* addresses,
        const BoundNetLog& source_net_log) override;
    void ChangeRequestPriority(RequestHandle req,
        RequestPriority priority) override;
    void CancelRequest(RequestHandle req) override;
    HostCache* GetHostCache() override;

private:
    class Job;

    int ResolveFromCacheInternal(const RequestInfo& info,
        const HostCache::Key& key,
        AddressList* addresses);

    Impl* const impl_;

    std::unique_ptr<HostCache> host_cache_;
    base::WeakPtrFactory<HostCache> host_cache_weak_factory_;

    base::ThreadChecker thread_checker_;

    DISALLOW_COPY_AND_ASSIGN(HostResolverMojo);
};

} // namespace net

#endif // NET_DNS_HOST_RESOLVER_MOJO_H_
